Transcript No Slide Title

MISSION:
• increase scientific literacy and public understanding
of the role of exotic species in ecosystems change.
• provide the tools and resources for citizens to actively
contribute in documenting the distributions of exotic
earthworms and their impacts across the region.
• train educators and other community leaders to help
build understanding of the methods and results of
scientific research about exotic earthworms and forest
ecosystems ecology.
The story of exotic earthworms began…
So…
How widespread are these invasions?
Earthworms - selected species and ecological groups:
Epigeic (litter dwelling) species: live & feed in forest floor; reddish brown, 2-8 cm
Dendrobaena octeadra / Dendrodrilus rubidus
Lumbricus rubellus
Endogeic (soil dwelling) species: live & feed in mineral soil; grey color; 7 – 12 cm
Octolasion tyrtaeum and Aporrectodea species
Anecic species: burrow deeply but feed on surface; red-brown; 10 – 20 cm
Lumbricus terrestris
Great Lakes Worm Watch
Illustrated guide to exotic earthworms
found in the Great Lakes Region
To use this guide you need :
1) 10x magnification
2) preserved earthworms
Earthworm anatomy and characteristics used in this key:
The presence or absence of pigmentation (usually brown or red-brown) is an important
feature that distinguishes different ecological groups of earthworms (details on page #).
The proboscis (mouth parts) type can vary among different earthworm
species and may be useful in identification (details on page #).
Earthworms have segmented bodies and various anatomical features
used for identification are located on different segments. Therefore,
you may need to count (from nose to tail) the number of segments to
determine the position of different features (details on page #).
The male pore is an external opening where sperm is released during
reproduction. It is often obvious due to glandular swelling. It is generally
on segment 15 (so useful when counting segments) but in some
earthworm species is on segments 14 or 13 so is a features useful for
identifying these particular species (details on page #).
The clitellum (a swollen band-like area near the head end of an
earthworm) and it’s associated features called the tuberculata
pubertatis (TP) and genital tumescence (GT) are part of the
reproductive system of and earthworm. Therefore, if an earthworm has
a clitellum, it is an adult and if not, it is a juvenile. The position, shape
and color of the clitellum and it’s TP and GT are important features
used to identify earthworm species (details on page #).
The setae are small hair-like projections on the body of earthworms. The setae are attached to
muscles and are used for locomotion. There are several different setae patterns which are
important features useful in identifying both adult and juvenile earthworm (details on page #).
Earthworm setae arrangements (1st of 3 pages):
The setae (hair-like projections) on each segment in European earthworm species (family Lumbricidae) appear as 8 long
rows running the length of the body. These rows are arranged relative to each other in one of three patterns. In the two most
common patterns, the rows are arranged in pairs that are either closely or widely spaced. NOTE: The difference between
closely and widely paired setae includes differences in the amount of space between the two rows of setae in each pair ( “A”
in illustrations), the distance between the pairs (“B” in illustrations), and the arrangement of the setae around the body.
Widely paired setae:
Closely paired setae:
A
B
Cross-sectional view (left) and ¾ view (right) of “closely
paired” setae pattern where distance B is much greater
than distance A and setae are clustered on the ventral (belly)
side of the earthworm.
A
B
Cross-sectional view (left) and ¾ view (right) of “widely
paired” setae pattern where distance B is only slightly
greater than distance A
Earthworm Segments: Various anatomical features used for identification of earthworm species are
often located in different places on the body for different species. Therefore, you may need to count
(from mouth to tail) the number of segments to determine the position of different features …
At the very top is
the proboscis, or mouth
segment 1
segment 2
segment 3
.
.
.
.
.
.
.
.
segment 15
(male pore)
.
.
.
.
.
segment 32
(start of clitellum)
.
.
segment 37
(end of clitellum)
.
.
Intersegmental
furrows
Segments,
separated by
and internal
membrane
called a septum
Sometimes furrows develop in the middle of a
segment. Don’t be fooled by the this and over
count the number of segments!
Segments
Intersegmental
furrows
Earthworm clitellum features:
The tuberculata pubertatis (TP) and genital tumescence (GT) are features associated with the earthworm’s clitellum. They
can vary in position, shape and color among different species, so are useful in identification. If the earthworm is not fully
mature, then these features may not be fully developed and you must take this into account when using these features for
identification. The function of the TP and GT are not fully understood, though we assume they play some role in reproduction!
• The tuberculata
pubertatis (TP), are
two slightly swollen
and usually differently
colored areas on each
side of the ventral
(belly) surface of the
clitellum.
• The genital
tumescence (GT), are
small swollen areas
around setae (so they
are often paired as are
the setae) on each
side of the ventral
surface of the clitellum.
GT may also be seen
above or below the
clitellum region or
associate with male &
female pores.
If this clitellum starts
on segment 25,
then…
The TP starts on
segment 26,
and…
The TP ends on
segment 29
Pairs of GT are present on
segments 24 through 31
in these images, indicated on
the left by grey arrows.
The shape and color of the TP and the number and positions of the GT vary quite a bit among species and some
species have none. So see the species descriptions for their particular characteristics.
Aporrectodea caliginosa complex (includes species A. caliginosa and A. tuberculata)
Both A. caliginosa & A. tuberculata are unique in
that they have a notched TP.
This group contain two very closely related and often
difficult to distinguish soil dwelling (endogeic) species
A. caliginosa and A. tuberculata, which are
separated by the patterns of their GT. If the clitellum
features are well developed enough to make the
distinction, then do so. If not, then these get lumped
into a single group called A. caliginosa complex.
Examples of underdeveloped clitellum features:
A. caliginosa (above) has GT on
alternating and consecutive segments
(27, 30, and 32 through 34). GT on segment
27 are not readily visible in the photograph
(left). This can often be the case, depending on
how well developed the clitellum is.
Both species have
closely paired setae
Other Identifying Features:
A. tuberculata (above) has GT on
• non-pigmented
alternating
segments only (30, 32, 34).
• male pores on segment 15
• clitellum on segments 27-34
• size ranges generally between 9-15 cm (AT)
• mouth proboscis is epilobic
When the TP are underdeveloped each can appear as
two circles or triangles side by side (see above). As the
feature develops, the two sections merge to form the
notched TP of the full adult. These species can
sometimes be confused with A. trapezoides which does
not have a notched TP.
What can I do?
1) Spread the word …
2) Prevent further introductions
by avoiding activities that we know
spread earthworms.
3) Alert us of new invasions!
www.greatlakeswormwatch.org